We show how dynamic nuclear polarization (DNP) enhanced solid-state NMR spectroscopy can be used to characterize polymorphs and solvates of organic solids. We applied DNP to three polymorphs and one hydrated form of the asthma drug molecule theophylline. For some forms of theophylline, sample grinding and impregnation with the radical-containing solution, which are necessary to prepare the samples for DNP, were found to induce polymorphic transitions or desolvation between some forms. We present protocols for sample preparation for solid-state magic-angle spinning (MAS) DNP experiments that avoid the polymorphic phase transitions in theophylline. These protocols include cryogrinding, grinding under inert atmosphere, and the appropriate choice of the impregnating liquid. By applying these procedures, we subsequently demonstrate that two-dimensional correlation experiments, such as 1H-13C and 1H-15N HETCOR or 13C-13C INADEQUATE, can be obtained at natural isotopic abundance in reasonable times, thus enabling more advanced structural characterization of polymorphs.
Enlightening the photoactive site of channelrhodopsin-2 by DNP-enhanced solid-state NMR spectroscopy
From The DNP-NMR Blog:
Enlightening the photoactive site of channelrhodopsin-2 by DNP-enhanced solid-state NMR spectroscopy
Becker-Baldus, J., et al., Enlightening the photoactive site of channelrhodopsin-2 by DNP-enhanced solid-state NMR spectroscopy. Proc. Nat. Aca. Sci. USA, 2015.
http://www.pnas.org/content/early/2015/07/23/1507713112.abstract
nmrlearner
News from NMR blogs
0
08-22-2015 11:20 AM
Is solid-state NMR enhanced by dynamic nuclear polarization?
From The DNP-NMR Blog:
Is solid-state NMR enhanced by dynamic nuclear polarization?
Lee, D., S. Hediger, and G. De Paepe, Is solid-state NMR enhanced by dynamic nuclear polarization? Solid State Nucl Magn Reson, 2015. 66-67C(0): p. 6-20.
http://www.ncbi.nlm.nih.gov/pubmed/25779337
nmrlearner
News from NMR blogs
0
05-02-2015 02:38 AM
Dynamic Nuclear Polarization Enhanced NMR in the Solid-State
From The DNP-NMR Blog:
Dynamic Nuclear Polarization Enhanced NMR in the Solid-State
Akbey, Ü., et al., Dynamic Nuclear Polarization Enhanced NMR in the Solid-State. 2013, Springer Berlin Heidelberg. p. 1-48.
http://dx.doi.org/10.1007/128_2013_436
nmrlearner
News from NMR blogs
0
08-26-2013 08:46 PM
[NMR paper] Dynamic Nuclear Polarization Enhanced NMR in the Solid-State.
Dynamic Nuclear Polarization Enhanced NMR in the Solid-State.
Dynamic Nuclear Polarization Enhanced NMR in the Solid-State.
Top Curr Chem. 2013 Jul 7;
Authors: Akbey U, Franks WT, Linden A, Rydmark MO, Lange S, Oschkinat H
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is one of the most commonly used spectroscopic techniques to obtain information on the structure and dynamics of biological and chemical materials. A variety of samples can be studied including solutions, crystalline solids, powders and hydrated protein...
nmrlearner
Journal club
0
07-09-2013 02:47 PM
[NMR paper] Synthesis, enhanced fusogenicity, and solid state NMR measurements of cross-linked HI
Synthesis, enhanced fusogenicity, and solid state NMR measurements of cross-linked HIV-1 fusion peptides.
Related Articles Synthesis, enhanced fusogenicity, and solid state NMR measurements of cross-linked HIV-1 fusion peptides.
Biochemistry. 2003 Apr 1;42(12):3527-35
Authors: Yang R, Yang J, Weliky DP
In the HIV-1 gp41 and other viral fusion proteins, the minimal oligomerization state is believed to be trimeric with three N-terminal fusion peptides inserting into the membrane in close proximity. Previous studies have demonstrated that the...
nmrlearner
Journal club
0
11-24-2010 09:01 PM
[NMR900 blog] Opportunities for studying polymorphs and cement-based materials via Ca-43 solid-stat
Opportunities for studying polymorphs and cement-based materials via Ca-43 solid-state NMR
June 11, 2010, University of Ottawa
Calcium is an important component in diverse materials and biochemicals. However, NMR spectroscopy of the only spin-active calcium isotope, Ca-43, is notoriously challenging due to its low natural abundance (0.14 %), low resonance frequency, and quadrupolar nature. Recently, researchers from the University of Ottawa, the NRC Steacie Institute for Molecular Sciences (SIMS-NRC), and Dalhousie University have independently reported advances in studies of inorganic...
nmrlearner
News from NMR blogs
0
08-22-2010 02:30 AM
[NMR900 blog] Opportunities for studying polymorphs and cement-based materials via Ca-43 solid-stat
Opportunities for studying polymorphs and cement-based materials via Ca-43 solid-state NMR
June 11, 2010, University of Ottawa
Calcium is an important component in diverse materials and biochemicals. However, NMR spectroscopy of the only spin-active calcium isotope, Ca-43, is notoriously challenging due to its low natural abundance (0.14 %), low resonance frequency, and quadrupolar nature. Recently, researchers from the University of Ottawa, the NRC Steacie Institute for Molecular Sciences (SIMS-NRC), and Dalhousie University have independently reported advances in studies of inorganic...
Polymorphs of Theophylline Characterized by DNP Enhanced Solid-State NMR
Linear Mode
